Article identification process and articles for practice thereof
First Claim
1. A process for identifying an article, which comprises:
- (a) applying a finely divided inorganic phosphor to said article,(b) exciting said phosphor to store energy therein by means of light free of infrared wavelengths,(c) observing any spontaneous decay phosphorescence of said phosphor in a darkened ambient,(d) stimulating said phosphor with infrared radiation, said stimulating producing an observable change in release of the previously stored energy,(e) observing the change in release of the previously stored energy as a change in luminescence of said phosphor as a result of said infrared stimulation.
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Accused Products
Abstract
Ordinary articles involved in transactions that require ascertaining authenticity of the article, such as wearing apparel, electronic parts, identification cards, or credit cards, may be identified as genuine through use of stimulatable inorganic phosphor compositions. The inorganic phosphors are applied to the article to be identified. The phosphors are excited to store energy therein, such as excitation by application of light as in a radiative photon process, or by application of thermal or electric fields as in a conductive process. The storage may be for however short or long a period. The result of storage is a later emission of real--time luminescence, sometimes called fluorescence, or of time-lag luminescence, sometimes called phosphorescence, or of no luminescence, where energy is either totally stored, converted to non-visible emissions such as infrared radiation, or internal conversion processed. The phosphors with stored energy as a result of this excitation are then stimulated during or after the excitation. The stimulation may be by use of light as in a radiative photon process, or by use of thermal or electric fields as in a conductive process. A change in emission of radiant energy from the phosphor as a result of the stimulation, such as change of luminescence of the phosphor, is then observed to verify the presence of the inorganic phosphor in the article. Such inorganic phosphors provide positive identification of the article because their behavior under the process steps above cannot be mimicked with organic compounds, and preparation of such inorganic phosphors, or phosphors capable of mimicking individual observed phenomena of the bona fide phosphor, especially preferred intermediate converter mixed phosphor type, is beyond the capability of counterfeiters. The behavior of such phosphors in response to the above process steps is also easily recognizable visually without use of complex analytical apparatus, thus providing an ideal forensic test.
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Citations
25 Claims
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1. A process for identifying an article, which comprises:
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(a) applying a finely divided inorganic phosphor to said article, (b) exciting said phosphor to store energy therein by means of light free of infrared wavelengths, (c) observing any spontaneous decay phosphorescence of said phosphor in a darkened ambient, (d) stimulating said phosphor with infrared radiation, said stimulating producing an observable change in release of the previously stored energy, (e) observing the change in release of the previously stored energy as a change in luminescence of said phosphor as a result of said infrared stimulation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 24)
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9. A process for identifying an article, which comprises:
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(a) applying a stimulatable inorganic phosphor to said article, (b) exciting said phosphor to store energy therein, (c) stimulating said phosphor in a manner different than said exciting, said stimulating producing an observable change in emission as radiant energy of the energy stored by said exciting, and (d) observing the change in emission of radiant energy from said phosphor as a result of said stimulating to verify the presence of the inorganic phosphor in said article. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18)
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- 19. An article of verifiable authenticity, comprising said article and a stimulatable inorganic phosphor applied to said article, excitation in a first manner and subsequent stimulation in a second manner different than the first manner of said phosphor providing a unique indicator of the presence of said phosphor.
Specification